Critical path method: find the tasks that set your end date
The critical path is the longest chain of linked tasks. It sets the earliest finish. A delay on it delays the whole project.
These are the eight planning threads the Krong course is built around. The highlighted ones are covered here. What are the planning threads?
Three ideas to know
- Predecessors. A task cannot start until the tasks it depends on finish.
- Forward pass. Work left to right to find the earliest start and finish of every task.
- Backward pass. Work right to left from the end date to find the latest start and finish. Float is the gap between the two.
The Caldera Freight schedule
Caldera Freight has 35 work packages and a 60-week duration. Eighteen of them have zero float. They form the critical path.
Look at the two rows in the middle of the chart. Model development and testing (1.3.2) is critical. Governance setup (1.1.4) is not. The PMO could start it late and the project would still finish on time, up to a point.
What to do with it
- Protect critical tasks. Put your best people and your earliest checks there.
- Use float on purpose. A task with spare weeks can absorb a delay, or lend resources.
- Watch for near-critical work. A task with one week of float is almost as important.
- Recalculate after every change. The path can move.
Why it is an integrated planning tool
A critical path is only as good as the data under it. Durations come from estimates. Predecessors come from the work breakdown. Owners come from the RACI matrix. Risks matter most when they sit on a critical task. In Caldera Freight, R-03 (algorithms may not reach the expected efficiency) attaches to component 1.3, where every work package is critical. It deserves tighter control than a risk on work with 24 weeks of float.
How Sen helps
Sen recalculates the path every time you change a duration or a link. The Gantt chart marks critical tasks in tangerine and shows float for the rest. You can zoom from one day to one month, and export the schedule to a task file for MS Project, Asana, monday.com or Jira.
Questions people ask
What is the critical path?
It is the longest sequence of dependent tasks in a project. It decides the earliest possible finish date.
What is float or slack?
Float is how long a task can be delayed without delaying the project end date. Tasks on the critical path have zero float.
Can a project have more than one critical path?
Yes. If two chains have the same total length, both are critical. Sen marks every task with zero float.
See it in a real plan
Open Sen and explore the Caldera Freight example. Every figure on this page comes from it. Copy it, change a task, and watch the plan move together.
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